3.2 engine dies when oil fill cap is removed
 

I've had this 1989 911 3.2 for 15 years it has 130,000 miles has always run well but when checking the oil the engine dies immediately after removing fill cap it has done this for as long as I have owned it. probably a vacuum line but could it be something else

Most likely the vacuum restrictor in the bigger breather line at the top of the oil tank is missing. It prevents a sudden drop so that the DME has a chance to regulate.

You need:
930-107-289-00-M260 Restrictor for Oil Tank Breather Hose, 911 (1981-89)
http://www.pelicanparts.com/cgi-bin/smart/more_info.cgi?pn=930-107-289-00-M260&catalog_description=&Restrictor%2520for%2520O il%2520Tank%2520Breather%2520Hose%252C%2520%2539%2 531%2531%2520%2528%2531%2539%2538%2531%252D%2538%2 539%2529%2520%2520

You will be able to check the oil level at idle!

I added one in my '75 to stop my tank from spilling into my airbox.

Thanks for the come back ill will check there first

Buy a $1.00 hose clamp set at hf ' to Check oil
Clamp breather hose check oil . 1 minute job

Shows that you probably don't have any vacuum leaks or minimal at least :-)

I like the clamp option. Or a needle nose vice grip to pinch it.